Soft-Templated Carbon Models Elucidate the Anomalous Increase of Capacitance in Nanopores

Abstract

Supercapacitors are electrochemical energy-storage devices distinguished by rapid charge–discharge and high power density. The observation of anomalously enhanced capacitance in nanoporous carbons challenged classical descriptions of double-layer charging and stimulated extensive in situ characterization and molecular modeling efforts. Yet the microscopic origin of this enhancement remains debated, with recent work questioning whether nanoscale confinement is the dominant factor and instead emphasizing the role of carbon disorder. Here we introduce a computational soft-templating protocol, powered by a machine-learning interatomic potential, to generate realistic disordered carbon architectures with controlled pore sizes. Using constant-potential molecular dynamics, we show that, at fixed structural disorder, capacitance increases as pore size decreases below 1 nm. These results reconcile earlier confinement-based interpretations with recent disorder-based views, providing a unified framework for charge storage in nanoporous carbons and design principles for next-generation supercapacitors.